Kidneys

2. Findings and Diagnosis

Axial CT – Bear Paw Sign
63-year-old female with a history of nephrolithiasis and chronic obstruction and a diagnosis of Xanthogranulomatous pyelonephritis (XGP).
Axial CT through the middle of the kidneys shows multiple, low attenuation obstructed calyces, surrounded by enhancing thin renal parenchyma. The appearance is reminiscent of the toe pads on a polar bear’s paw. The patient did have a history of TB
Ashley Davidoff MD TheCommonVein.net 24526